This dissertation research will investigate the interrelationships of culture, assessment and.congruence (often called accuracy or detection) in service access for Native American substance using, high risk youth 13 -18, on both an urban and reservation setting. Although access to service does not insure improved functioning, without recognition of problems by gateway providers, and without subsequent access to services, treatment can not be received. By explicating the role of the potentially modifiable culture-related predictors (youth cultural identity, provider cultural competence and sector culturally relevant services), this study provides needed knowledge to directly improve service 0access and continuance in youth with substance and mental health problems. Using the Adolescent American Indian Multisector Help Inquiry (Arlene Stiffman, Ph.D., PI), interviews of 400 American Indian youth (200 youth from the Pima-Maricopa Indian Reservation and 200 youth of mixed tribes from the Phoenix, Arizona area) and 600 people who helped them with their problems from multiple sectors, data will be used to construct variables for this research. In addition, some measures will be added to AIM-HI by this research, and providers will be interviewed a second time. This cross-sectional data will be used to test the following aims: 1. To examine how congruence between provider assessment and youth report is affected by three cultural factors: cultural identification; cultural competence; and culturally relevant services. 2. To examine how access to service for both substance abuse and mental health disorders is affected by culturally services and assessment congruence. Bivariate analysis, multiple regression and structural equation modeling will be used to test the aims. A model is specified based on access models and a model of how culture effects services (Andersen & Newman, 1973; Andersen, 1995; Aponte & Johnson, 2000; Costello et al., 1998). This dissertation research explicates factors which can be modified to improve access in an understudied, high need population of substance using American Indian youth.